package com.hmdp.service.impl;

import cn.hutool.json.JSONUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.ShopType;
import com.hmdp.mapper.ShopTypeMapper;
import com.hmdp.service.IShopTypeService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

import java.util.List;

import static com.hmdp.utils.RedisConstants.CACHE_SHOP_TYPE;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class ShopTypeServiceImpl extends ServiceImpl<ShopTypeMapper, ShopType> implements IShopTypeService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Override
    public Result queryTypeList() {
        //先查缓存
        List<String> shopTypeList = stringRedisTemplate.opsForList().range(CACHE_SHOP_TYPE, 0, 9);
        if (shopTypeList != null && !shopTypeList.isEmpty()) {
            return Result.ok(JSONUtil.toList(shopTypeList.get(0),ShopType.class));
        }
        //没有查数据库
        List<ShopType> shopTypes = query().orderByAsc("sort").list();
        //数据库没有则报错
        if (shopTypes == null || shopTypes.isEmpty()) {
            return Result.fail("首页列表数据异常");
        }
        String shopTypesToString = JSONUtil.toJsonStr(shopTypes);
        stringRedisTemplate.opsForList().leftPushAll(CACHE_SHOP_TYPE,shopTypesToString);
        return Result.ok(shopTypes);
    }
}
